Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
The present disclosure is generally directed to bus connector assemblies for use with an electric power switching apparatus. More specifically, the present disclosure is generally directed to a bus connector for use with an electric power switching apparatus with isolation means such as a transfer switch or a circuit breaker. Such connector assemblies allow the switching apparatus to achieve a very high withstand current ratings. For example, the high withstand current rating may be 100,000 amperes or above. In one arrangement, the present disclosure relates generally to a connector assembly arrangement that may be used for interconnection between a device and a bus structure. More particularly, the connector assembly arrangement may be used in an isolation-bypass automatic transfer switch. However, aspects of the present disclosure may be equally applicable in other scenarios as well.
An automatic transfer switch is designed to provide a continuous source of power for critical loads by automatically transferring from a normal power source to an emergency power source when the normal power source falls below a preset limit. Automatic transfer switches are in widespread use in, e.g., airports, subways, schools, hospitals, military installations, industrial sites, and commercial buildings equipped with secondary power sources and where even brief power interruptions can be costly or perhaps even life threatening. Transfer switches operate, for example, to transfer a power consuming load from a circuit with a normal power supply to a circuit with an auxiliary power supply. A transfer switch can control electrical connection of utility power lines and the diesel generator to facility load buses. In certain installations, the transfer switch automatically starts a standby generator and connects the standby generator to the load bus upon loss of utility power. In addition, the transfer switch can automatically reconnect the utility power to the load bus if utility power is reestablished.
Automatic transfer switches are typically of two types: (i) an automatic transfer switch comprised of a single switching apparatus mounted in an enclosure; and (ii) an automatic transfer switch interconnected with a redundant switch (e.g., manual or automatic switch) mounted in a single enclosure or in multiple adjacent enclosures. This second configuration is typically referred to as a bypass-isolation transfer switch. Typically, one or both switches are provided with isolation means allowing disconnecting the switch from a bus structure and removal out of the enclosure.